1. Field of the Invention
The present invention relates to a process for producing a coated preparation. More specifically, it relates to a process for producing a coated preparation in the form of finely divided particles which is composed of a core material of a useful hydrophilic material, in particular, an organic acid or its salt, coated with one or more coating layers of a coat material selected from hydrophobic hot-melt lipid to minimize the external influence on the core material or the influence on surroundings by the core material and to improve blocking between coated particles.
Further, the present invention relates to a water-soluble vitamin preparation having an improved flavor which utilizes the process of the present invention, and its production process. More specifically, it also relates to a water-soluble vitamin preparation useful as medicines and health food in which an unpleasant flavor of a water-soluble vitamin is improved, a dissolution rate of a water-soluble vitamin in water is reduced to provide slow-release properties, reactions between components are inhibited, and preparation properties are improved, as well as its production process.
2. Disclosure of the Prior Art
Organic acids such as citric acid, fumaric acid, and sorbic acid are widely used as, for example, acidulants, pH adjusting agents, preservatives, and the like. However, in many cases, adverse influences due to low pH are observed during processing and storage of food products and the like.
In addition, the organic acid, L-ascorbic acid, is widely utilized in various food, health food, feed, medicines, and the like, for example, as a quality improving agent, an acidulant, a nutrient enhancer as vitamin C, a medicament, and the like.
In the utilization of L-ascorbic acid as a quality improving agent, its oxidative and reductive reactivity is expected. However, the reaction rate is too fast to last its improving effect for extended periods of time. On the other hand, in the utilization of L-ascorbic acid as an enhancer, it should be kept stably during production and storage of food and the like. However, it is very difficult to keep L-ascorbic acid stably, in particular, in the presence of water, oxygen, metal salts and the like, resulting in such a drawback that the desired function cannot be exhibited and, sometimes, its oxidative and reductive reactivity adversely influences another component.
Then, for solving these problems, processes for producing coated preparations have been proposed to prevent these organic acids from contact with water, oxygen and the like and to control its reactivity. In these processes, an organic acid is used as a core material and a coat of a hydrophobic material is provided about the surface of the core material. For example, a fine powder of an organic acid is coated with a hydrophobic material such as a hot-melt fat which is a solid at room temperature by a spray cooling method, a spray coating method, a rotary mixing-drying method, or the like.
In particular, for example, JP-A 63-164863, JP-A 63-164864 and JP-A 63-258813 propose a process for producing a coated preparation in which a core material such as a water-soluble vitamin powder or an organic acid powder is brought into contact with and hit by a coat material such as a fat so that the coat material adheres to the core material to cover it. JP-A 55-92661, JP-B 62-18152, JP-A 64-3118 and JP-A 64-3119 propose a process for producing a fine powder preparation in which finely divided organic particles and a melted fat are mixed at an elevated temperature and then the mixture is spray-cooled. JP-A 50-52221 proposed a process for coating organic acid particles in which fat is dissolved in a solvent and an organic acid is covered with resultant solution in a fluidized bed device with evaporating the solvent. Further, for improving the degree of covering with a coat material and solving the problem of simplicity and convenience in these processes, Japanese Patent Application No. 9-13702 (JP-A 10-203965) filed by the present assignee propose a process for producing a coated preparation in which a coat material melted with heating is continuously or intermittently added to a hydrophilic core material with mixing the core material at a temperature of the coat material to solidify the coat material to form plurality of coating layers about the core material.
However, in the above known processes, there are such problems that inhibition of dissolution of a core material such as an organic acid in water is insufficient or very difficult and, even if the dissolution can be prevented, productivity of the processes is very low from the economical view point. Moreover, there is a problem of blocking between particles coated with a hydrophobic hot-melt coat material during production steps.
One main object of the present invention is to provide a process for producing a coated preparation which can inhibit the dissolution of the core material in water and can prevent blocking between coated particles during production steps by improving covering with a coat material to solve the above problems in the prior art processes.
This object as well as other objects and advantages of the present invention will become apparent to those skilled in the art from the following description.
The present inventors have studied intensively to achieve the above object. As a result, the present inventors have found that it is necessary to accelerate xcex2-form crystallization of one or more coating layers composed of a coat material selected from hydrophobic hot-melt liquid upon coating about a hydrophilic core material, thereby improving covering of the core material to give a coated preparation having a low degree of dissolution in water in a high yield and, at the same time, to prevent blocking during production steps of the preparation.
In addition, although, among water-soluble vitamins, there are many substances having unpleasant flavors such as peculiar vitamin odors, bitterness and the like, the present inventors also have found that these unpleasant flavors can be improved by the process of the present invention or that disclosed by the above present assignee""s Japanese Patent Application No. 9-13702 (JP-A 10-203965) in combination with sweeteners. That is, sweeteners such as aspartame and the like have been used for improving unpleasant flavors of water-soluble vitamins (JP-A 60-192571, JP-A 8-208517, etc.). Further sweeteners such as aspartame and the like have been used not only for improving unpleasant flavors but also as components of various vitamin preparation (JP-A 60-19474, JP-A 9-157174, JP-A 9-95447, Japanese Patent No. 2574176, etc.). Nevertheless, surprisingly, the present inventors have found that water-soluble vitamin preparation having a further improved flavor and various improved properties can be obtained by combining the process of the present invention or that disclosed by Japanese Patent Application No. 9-13702 (JP-A 10-203965) and a sweetener such as aspartame.
Then, the present invention provides:
(1) a process for producing a coated preparation comprising a hydrophilic core material coated with a coat material selected from hydrophobic hot-melt lipid;
said process comprising adding the melted coat material dropwise to the core material with fluidizing the core material at a temperature not higher than the solidification temperature of the coat material in the presence of xcex2-form seed crystals of the coat material to solidify the coat material to form at least one coating layer about the core material; or
adding the melted coat material dropwise to the core material with fluidizing the core material at a temperature not higher than the solidification temperature of the coat material to solidify the coat material to form at lease one coating layer about the core material, followed by adding xcex2-form seed crystals of the coat material, for example, within 10 minutes, to accelerate xcex2-form crystallization of the coating layer;
(2) the process according to the above (1), wherein the core material is at least one organic material selected from the group consisting of organic acids, organic acid salts and non-organic acid vitamins;
(3) the process according to the above (2), wherein the core material is L-ascorbic acid or its salt;
(4) the process according to the above (1), wherein the coat material is at least one material selected from the group consisting of fats and oils, fatty acids, fatty acid esters, their hydrogenated products and wax;
(5) the process according to the above (1), wherein the xcex2-form seed crystals of the coat material are a part of the coated preparation prepared separately;
(6) the process according to the above (1), wherein xcex2-form seed crystals of the coat material is prepared separately by melting the coat material and adjusting its temperature;
(7) the process according to the above (1), wherein xcex2-form crystallization is carried out by holding the coating layer at a pre-determined temperature after formation thereof;
(8) the process according to the above (1), wherein the core material is fluidized in a temperature controllable stirring-mixing device;
(9) the process according to the above (1), wherein xcex2-form seed crystals of the coat material is used in an amount of 0.1 to 30% by weight based on the total weight of the coated preparation; and
(10) the process according to the above (1), wherein the core materials is formulated in an amount of 50 to 97% by weight based on the total weight of the coated preparation.
According to these aspects of the present invention, the coated preparation of the hydrophilic core material having improved stability whose dissolution in water is inhibited can be simply and conveniently obtained with preventing blocking by properly selecting the coat material and its amount to be coated, i.e., the number of coating layers and the rate of addition, adding xcex2-form seed crystals of the coat material, and properly controlling temperature to accelerate xcex2-form crystallization of the coating layer.
The present invention further provides:
(11) a water-soluble vitamin preparation having an improved flavor which comprises a coated water-soluble vitamin component, a sweetener and an excipient; and
said coated vitamin component obtained by coating a water-soluble vitamin core material having an unpleasant flavor with at least one coating layer of a coat material selected from hydrophobic hot-melt lipid which is formed by melting, adding and solidifying the coat material with fluidizing the core material;
(12) the water-soluble vitamin preparation according to the above (11), wherein the core material is a water-soluble vitamin selected from the group consisting of calcium ascorbate, sodium ascorbate, nicotinic acid, nicotinamide, vitamin B1""s, riboflavin, riboflavin phosphate sodium, pantothenic acid, sodium pantothenate and pyridoxine hydrochloride;
(13) the water-soluble vitamin preparation according to the above (12), wherein the core material is calcium L-ascorbate;
(14) the water-soluble vitamin preparation according to the above (11), wherein the coat material is at least one material-selected from the group consisting of fats and oils, fatty acids, fatty acid esters, their hydrogenated materials and wax;
(15) the water-soluble vitamin preparation according to the above (11), wherein the coating layer is crystallized in xcex2-form crystals;
(16) the water-soluble vitamin preparation according to the above (11), wherein the water-soluble vitamin content of the coated water-soluble vitamin component is 30 to 97% by weight;
(17) the water-soluble vitamin preparation according to the above (11), wherein the sweetener is at least one material selected from the group consisting of aspartame, potassium acesulfame, sucrarose, sodium saccharin and licorice extract;
(18) the water-soluble vitamin preparation according to the above (17), wherein the sweetener content of the preparation is 0.1 to 5.0% by weight; and
(19) the water-soluble vitamin preparation according to the above (11), wherein the preparation is in the form of powder, granules, tablets or capsules.
Furthermore, the present invention provides:
(20) a process for producing a water-soluble vitamin preparation having an improved flavor which comprises the steps of:
coating a water-soluble vitamin core material having an unpleasant flavor with at least one coating layer of a coat material selected from hydrophobic hot-melt lipid which is formed by melting, adding and solidifying the coat material with fluidizing the core material to obtain a coated water-soluble vitamin component, and
compounding the coated water-soluble vitamin component with a sweetener and an excipient;
(21) a process for producing a water-soluble vitamin preparation having an improved flavor which comprises the steps of:
coating a water-soluble vitamin core material having an unpleasant flavor with at least one coating layer of a coat material selected from hydrophobic hot-melt lipid,
said coating layer being formed by melting, adding and solidifying the coat material with fluidizing the core material in the presence of xcex2-form seed crystals of the coat material, or melting, adding and solidifying the coat material with fluidizing the core material, followed by adding xcex2-form seed crystals of the coat material to accelerate xcex2-form crystallization of the coating layer, to obtain a coated water-soluble vitamin component, and
compounding the coated water-soluble vitamin component with a sweetener and an excipient;
(22) accelerate xcex2-form crystallization of the coating layer the process according to the above (21), wherein the xcex2-form seed crystals of the coat material are a part of the coated water-soluble vitamin component prepared separately;
(23) the process according to the above (21), wherein xcex2-form seed crystals of the coat material is prepared separately by melting the coat material and adjusting its temperature;
(24) the process according to the above (21), wherein xcex2-form crystallization is carried out by holding the coating layer at a pre-determined temperature after formation thereof;
(25) the process according to the above (21), wherein xcex2-form seed crystals of the coat material is used in an amount of 0.1 to 30% by weight based on the total weight of the water-soluble vitamin component; and
(26) the process according to the above (20) or (21), wherein the core material is fluidized in a temperature controllable stirring-mixing device.
According to the latter aspects of the present invention, a water-soluble vitamin preparation useful as medicines and health food can be obtained. In the water-soluble vitamin preparation of the present invention, an unpleasant flavor of a water-soluble vitamin is improved to reduce an unpleasant flavor in the mouth; a dissolution rate of a water-soluble vitamin in water is reduced to provide slow-release properties; reactions between components are inhibited; and preparation properties are improved.